libopc/third_party/libxml2-2.7.7/test/relaxng/tutor10_7.rng

<element name="addressBook" ns="http://www.example.com"
         xmlns="http://relaxng.org/ns/structure/1.0">
  <zeroOrMore>
    <element name="card">
      <attribute name="name"/>
      <attribute name="email"/>
    </element>
  </zeroOrMore>
</element>